The present invention relates broadly to the alignment of objects, and in particular to the automatic alignment of an x-ray mask on a semiconductor slice.
In many manufacturing processes the automatic alignment of one object with respect to a second object is desirable. It is particularly desirable during the production of semiconductor devices to align automatically semiconductor wafers and metallization masks wherein the masks are used to define the areas of these wafers to be etched, diffused, or otherwise operated on. Typically, because of the small sizes of both the wafers and the masks and the difficulty of automatically placing each mask on a wafer, the masks are placed on and aligned with the wafer manually. An operator is required to view each wafer and the overlying mask through a microscope. The adjustments of the relative positions of the wafer and the mask are made by the operator until satisfactory alignment of the two is obtained. However, there are the inherent inaccuracies which are introduced by the human operator, thus the resulting defined areas of the wafer are often not located as accurately as may be desired.